Syringe, column or the like



NOV. 21, 1967 J. F, MCLAY SYRINGE, COLUMN OR THE LIKE Filed May 24, 19652 Sheets-Sheet l Arr /w--xY JOSEP/v F. Mc AY -Q m--- w l. m w f Nov. 2l,1967 v x. F. McLAY 3,353,718

SYHINGE, COLUMN OR THE LIKE Filed May 24, 196e v r.2 sheets-shewb 2 IJfE/D/-l BY A raf/Vix United States Patent O Pennsylvania Filed May 24,1966, Ser. No. 552,519 14 Claims. (Cl. 222 158) The present inventionrelates to a new and useful pistondrive construction for liquid-tightand gas-tight syringes used in chemical analysis and for othermicro-metering chemical apparatus and the like, and also relates tocertain other new and useful constructional features of such syringesand the like, as indicated more fully in the following description andaccompanying drawings.

One of the objects of the present invention is to provide a screw-feedfor the plunger or piston of a gas-sampling syringe or for the piston orplunger of micro-metering cylinder-and-piston chemical apparatus whichwill provide the desired fine adjustment of the travel or of theposition of the plunger or piston and provide, optionally, a rapidadvancement and retraction of the plunger free of the screw-feed thereofand a tine screw-feed advancement and retraction of the piston, and willalso provide for a rapid and convenient change-over from screw-feed tonon-screw-feed movement of the piston.

Another object of the present invention is to provide a gas-tight andHuid-tight plunger or piston for syringes and for other column typechemical apparatus and the like, whose position may be adjusted by linescrew-feed and which may be retracted free of the screw connection.

With the above and other objects in view, which will appear more fullyhereinafter, the present invention consists of the novel constructionsand constructional features hereinafter described and shown in theaccompanying drawings and set out in the claims hereinafter appearing.

In the accompanying drawings, hereinafter described, likereference-characters indicate like parts.

FIGURE 1 represents an elevational View of a syringe representing oneembodiment of the present invention, with the tapered needle-receivingtip of the glass syringe body and with the metallic needle-attachingsleeve or hub shown in cross-section.

FIGURE 2 represents a cross-sectional View l(partly broken away) on line2 2 of FIGURE l, on a scale approximately ythree times that of FIGURE 1with the piston-coupling slider shown in its uncoupled position.

FIGURE 3 represents a cross-sectional View on line 3 3 of FIGURE 4.

FIGURE 4 represents a cross-sectional view on line 4 4 of FIGURE 2.

FIGURE 5 represents an elevational view of the piston and f the lowerend of the piston-rod-shown partly in cross-section in line 5 of FIGURE2.

FIGURE 6 is a cross-sectional view of the top of the syringe shown inFIGURE 2, but with the piston-coupling slider shown in its couplingposition.

FIGURE 7 represents a top plan view, generally on line 7 7 of FIGURE 2,but on a scale approximately two-thirds of the scale of FIGURE 2, andwith the slider shown in its uncoupled position (as in FIGURE 2).

FIGURE 8 represents a top plan View, similar to that shown in FIGURE 7,taken generally on line 8 8 of FIGURE 6, showing the slider in itsthread-engaging or coupling position.

FIGURE 9 shows a perspective view of the slider-housing and slidertherein, with the slider shown in its uncounling position (as in FIGURE2).

FIGURE 10 represents a similar perspective view of the slider-housingand slider therein, with the slider shown in its thread-engaging orcoupling position (as in FIG- URES 6 and 8).

ICC

FIGURE 1l represents a top plan view of the slider.

The syringe, as shown in FIGURES l to 5, inclusive, includes a generallycylindrical transparent glass syringebody or barrel 1, having a glazedcylindrical precision 'bore 2 of suitable length, an enlarged andinternallythreaded upper or rear end-portion or head 3 having internalscrew-threads 4 whose inner diameter is substantially larger than theinner diameter of the bore 2 of the barrel of the syringe. In theembodiment shown in FIG- URES l to 5 of the drawings, the diameter ofthe bore 2 is 0.1920", and the wall-thickness of the portion of theglass barrel which is coextensive with the metering bore 2 is of theyorder of 0.100. The lower or front end portion of the glasssyringe-body 1 is contracted to form the reduceddiametered taperedneedle-receiving tip 5 of suitable length, whose taper has an includedangle of the order of 3 degrees and 26 minutes. The length of thetapered portion of the tip 5 is of the order of a quarter of an inch,and its diameter at its small end is of the order of a quarter of aninch, more or less.

The outer tapered surface of the tip 5 is finely ground or provided witha fine-ground finish, so as to form a good frictional as well asduid-tight engagement with the similiarly tapered polished inner bore ofneedle-hub 6 formed of suitable metal, as for instance, stainless steelor the like. A

The needle-hub 6 includes a tubular needle-receiving eX- tension orcannula-receiving socket 7, into which the hypodermic needle or cannula8 or the like is telescoped and in which it is firmly secured, in afluid-tight seal therewith, by swaging or silver-soldering or the like.The interft between the outer finely-ground tapered surface of the tip 5and the similarly tapered bore of the needle-hub 6 is such as will alsoprovide a gas-tight seal between the needle-hub 6 and the glass tip 5.

A multi-ring or multi-land piston 9 is disposed within the glazedprecision bore 2 of the glass syringe barrel 1. The piston 9 is formedof Tellen or Kel-F or other suitable generally chemically inertform-retaining though slightly resiliently deformable synthetic resinwhich will from an unlubricated non-seizing slidable Huid-sealingcontact with a glazed glass surface. The main body of the piston 9, asat 10, is of a diameter slightly less than the inner diameter of theprecision bore 2 of the glass barrel 1. At each of the two ends of thepiston 9 a relatively narrow cylindrical piston-ring or land 11 isformed integrally with the piston (as indicated in FIGURES 2 and 5 theaxial width of each of these piston-rings being generally of the orderof 0.040 in the embodiment indicated in FIGURES 1 to 5.

The diameter of the integral piston-rings or lands 11 is slightly largerthan the diameter of the bore 2. Thus, for instance, with the bore 2 ofthe glass barrel having an inner diameter of 0.192, the outer diameterof each of the piston-rings or lands 11 would be of the order between0.194 to 0.196 in their uncompressed condition, so that when the piston9 is inserted into the cylindrical bore 2, the integral piston-rings orlands 11 will be slightly compressed and hence will resiliently bearagainst the cylindrical bore 2 with a relatively high pressure per unitof contact-area thereof.

The chamfered or tapered bore-portion 12 intervening the cylindricalbore 2 and the threaded bore 4, serves to vguide the larger-diameteredring-portions 11 of the piston 9 into the bore 2 and to compress them tothe borediameter as the piston 9 is inserted into the glass housing orbarrel 1.

A piston-operating stem or rod, designated generally by the numeral 13,is preferably formed of stainless steel and is threaded throughout themajor portion 14 of its length, namely, over a portion of its lengthsufficiently greater than the scale-length, so that such threadedportion 14 can be maintained in threaded engagement with the threadedportion 32 of the coupling-slider 16 throughout the scale-length travelof the piston 9, while the slider 16 is in its coupling position shownin FIGURES 6 and 8.

Thus, with an overall scale-length of 2.109, which also represents thenecessary screw-coupled piston-travel, the threaded portion 14 of thepiston-stem 13 will have a length more or less of the order of two andthree-eighths of an inch.

The piston-operating rod or stem 13 has a tubular inner end 17 whoseinternally screw-threaded bore portion 18 receives the externallythreaded integral stem 19 of the piston 9; these two threaded portionsbeing tightly screwthreaded in relation to each other, `and the stem 19is secured against being unscrewed from the piston-rod by a thin lm ofan epoxy resin intervening the two threaded surfaces. Prior tothreadedly telescoping the integral stem 19 of the piston 9 into thethreaded bore of the inner end-portion 17 of the stainless-steelpiston-rod 13, the externally threaded portion of the stem 19 (formed ofTeon, Kel-F or the like) is treated for a minute or so with acomposition of anhydrous ammonia and an alkali metal such as sodium,namely, until a Very slight adherent carbon layer is formed on theexternal threadssuch carbon layer being recognizable by the threadsgradually turning from their initially generally white or egg-shellcolor to a brown color of an increasingly degree of darkness as thetreatment is continued. Thereafter the so threaded external threads ofthe stern 19 are coated with a small amount or thin layer of an epoxyresin, or such epoxy resin may be applied to the internally threadedbore 18 of the terminal-portion 17 of the piston-rod 13. The integralstem 19 of the piston 9 is then screw-threadedly telescoped into theinternally threaded bore 18, until it is tight therein, and the epoxyresin is then permitted to set. Any excess of the epoxy resin which maybe extruded at 1S may then be scraped of. Other excess of such epoxyresin may lodge between the inner end of the. stem 19 and the inner endAof the threaded bore 18.

The piston-operating stem 13 has a reduced-diametered 'outer end 20, towhich a knurled knob or other suitable handle device 21 is detachablysecured by a set-screw 22 or the like;

A coupler-housing designated generally by the numeral 23 (FIGURE 9), isprovided at the head end of the glass barrel 1 and includes an outerchanneled head-like slidereceiving portion `24 and an innerexternally-threaded bushing portion 25. The inner bushing portion 25 isscrewthreaded into the internally-threaded head portion 3 of the glasssyringe body or barrel, with the flat bottom surface 26 of theslider-receiving portion 24 (of the coupler-housing 23) bearing tightlyagainst the upper flat end-surface 27l of the glass barrel 1. Thecoupler-housing 23 may be formed of a form-retaining synthetic resinsuch as the chlorinated polyethers, of which a commercially availableform is marketed under the trademark Penton by the Hercules PowderCompany, or it may be formed of Teflon or Kel-F or the like or otherimpact-resistant chemically'inert synthetic resin.

The inner cylindrical bore 28 of the tubular bushing portion 25 of thecoupler-housing 23 is slightly greater than the uncompressed diameter ofthe piston rings 11 of the piston 9, so that when the coupler-slider 16is in its uncoupled position as shown in FIGURES 2, 7 and 9, the entirepiston 9 may be fully withdrawn from the glass barrel 1 as well as fromthe coupler-housing 23 and slider 16; the outer diameter of the threadedportion 14 of the piston-operating stem 13 being slightly smaller thanthe Y'diameter of the bore 2 of the glass barrel 1.

The head portion 24 of the coupler-housing 23 has a transverseslider-guiding channel 29` therein (FIGURES 1, 6, 9 and 10) with twoinwardly extending flanges 30 overlying the longitudinal marginal zonesof the couplerslider 16, as indicated in FIGURES 1 and 2 and 6 to l0-whereby the ,coupler-slider 16 is fully confined within the 4- lieadportion 24 of the coupler-housing 23 in a manner which permits theslider 16 to be slid transversely of the coupler-housing 23.

The slider 16 is formed of a resilient impact-resistant synthetic resinsuch as Teon or Kel-F or nylon or the like, and -has two intersectingholes 31 and 32 extending therethrough (FIGURES 7 to 11); the largerhole 31 being of a diameter sufliciently larger than the uncompresseddiameter of the piston-rings 11 so as to clear both the screw-thread 14of` the piston-operating rod 13 as well as the piston-rings 11 with anadequate margin for easy removal, while the smaller hole 32l is threadedand is of a diameter and has its thread of a pitch corresponding to thediameter and pitch of the screw-threaded portion 14 of thepiston-operating rod 13; so that when the screw-threaded portion 14 o-fsuch rod 13 nests within the threaded hole 32, it forms a neat threadedengagement therewith, so that the turning of the rod 13 will move thepiston 9 (in the bore 2 of the glass barrel 1) in either direction, asmay be desired, according to the direction of turning of the rod 13.

The two holes 31 and 32 intersect each other or overlap each other tosuch an extent that approximately a segment of the hole 32 is vremovedby such intersection with the hole 31, and so that the threads withinthe hole 32, between the points 33 (FIGURE 11'), will occupyapproximately 245 of a circle, except possibly for the slightinterruption at 34 (FIGURE 7).

A small hole 35 is formed through the slider 16, with its axis in theplane in which the axes of the holes 31 and 32 lie, and a thin or narrowslot or slit 36 is formed between the threaded hole 32 and the smallhole 35. By this means the threaded hole 32 may be resiliently enlargedor expanded in the direction of the arrows 37 (FIGURE 11); sufficientlyto permit the threaded portion 14 of the piston-operating rod 13 to passthrough the mouth 33 of theslider when it is desired to move the slider16 from its uncoupled position (as shown in FIG- URES 2, 6 and 9 intoits coupling position (as shown in FIGURES 6, 8 and 10), or vice versa.

The precision-bore 2 of the glass barrel 1 terminates in a flattransverse terminal wall 3S. An axial hole 39, of minimum diameter,extends from the flat bottom 38 of the precision-bore 2 of the barrel 1to the outer chamfered end 40k of the externally tapered tip 5 of theglass barrel-the hole 39 being of the order of a 1/32" to 1A6" (more orless).

The syringe hereinabove described and illustrated in the accompanyingdrawings is suitable for sampling and for the injection of the-samples,of both in gas analysis and in isothermal molecular-weightdeterminations, wherein it may be effectively used as accurate andreadily manipulable sampling pipette of high accuracy.

Having described and illustrated exemplifying embodiments of myinvention, I claim the following:

1. A syringe, column or the like, including a rigid transparent glassbarrel having a glazed cylindrical bore, a piston operatively disposedtherein, said piston being formed of a generally chemically inertform-retaining though slightly resiliently deformable synthetic resinforming an unlubricated non-seizing slidable fluid-sealing dry contactwith the glazed bore of said glass barrel and said piston having adiameter whichl in its uncompressed. condition is slightly greater thanthat of the -bore of said glass barrel a piston-rod operativelyconnected with said piston and extending through and beyond an end ofsaid barrel and having a portion thereof externally screw-threaded forthreaded engagement with the belowmentioned coupling-slider, acoupler-housing operatively connected with the end of said barrelthrough which said piston-rod extends and having a rod-passagewaytherethrough, generally co-axial with said barrel, through which saidpiston-rod extends, said rod-passageway being greater than saiduncompressed diameter of the piston, said coupler-housing having aslider-guide extending transversely of the axis of said rod-passageway,and a coupling-slider slidably disposed within said slider-guide andconfined therein in an axial direction and having a screw-threadedrod-coupling portion for threadedly engaging the threaded portion of thepiston-rod and a rod-clearance portion for clearing the threaded portionof the pistonrod, said rod-clearance portion of said coupling-sliderbeing greater than said uncompressed diameter of said piston andpermitting the passage of said piston therethrough, sai-dcoupling-slider having a rod-coupling position in said slider-guide inwhich it threadedly engages the threaded portions of the piston-rod andhaving an uncoupling position in which it clears the threaded portion ofthe piston-rod, and said couplingslider being arranged to permit it tobe moved in said slider-guide from either of its said two positions tothe other, thereby to permit the screw-controlled displacement of thepiston in either direction in accurate small increments when thecoupling-slider is in its coupling position and to permit thedisplacement of the piston in either direction, free of said;screw-threads, when the coupling-slider is in its uncoupling position,and to permit the piston to be fully withdrawn through saidrod-clearance portion of the coupling-slider and through saidcoupler-housing.

2. A device according to claim 1, in which the coupling-slider isinternally screw-threaded.

3. A device according to claim 1, in which the coupling-slider has twointersecting holes therethrough with their axes generally parallel witheach other and with the axis of the barrel, one of said holes being arod-clearance hole and the other of said holes being an internallythreaded rod-coupling hole.

4. A device according to claim 1, in which the pistonrod limits thetravel of the coupling-slider within the slider-guide.

5. A device according to claim 2, in which the pistonrod limits thetravel of the coupling-slider within the slider-guide.

6. A device according to claim 2, in which the circumference of theinternal screw-thread of the couplingslider is substantially less than360.

7. A device according to claim 6, in which there is a gap ofsubstantially less than 180 in the circumference of the internalscrew-thread of the coupling-slider, through which the screw-t-hreadedportion of the pistonrod may enter into threaded engagement with suchscrewthread of the coupling-slider and through which it may exit fromsuch screw-threaded engagement.

S. A device according to claim 7, in which the gap in the screw-threadof the slider is resiliently expandable by the ingress and egress of thescrew-threaded portion of the piston-rod therethrough.

9. A device according to claim 3,V in which the intersection of the twoholes forms a gap in the internallythreaded hole of substantially lessthan 180.

10. A device according to claim 9, in which the gap in thescrew-threaded hole is expandable by the ingress and egress therethroughof the threaded portion of the piston-rod.

11. A syringe, column or the like, including a rigid transparent glassbarrel having a glazed cylindrical bore and a discharge hole ofsubstantially smaller diameter eX- tending from the inner end of saidbore to the exterior of the barrel and said barrel having its other endscrewthreaded, a piston operatively disposed within said bore formed ofa generally chemically inert and generally form-retaining thoughslightly resiliently deformable synthetic resin capable of forming anunlubricated nonseizing slidable fluid-sealing dry contact with theglazed surface of said bore, said piston having an integral piston-ringin proximity of each of its two ends, said piston-rings being of smallaxial extent and of a diameter which is larger than the diameter of itsbody portion intermediate the piston-rings thereof and which issufficiently larger than the bore of the barrel in the uncompressedcondition thereof so as to be resiliently compressed when the piston isoperatively disposed in the bore of the barrel, a piston-rod having itsinner end afxed to the piston and having a portion thereof externallyscrew-threaded and having an end thereof extending beyond the barrel andbeyond the below-mentioned coupler-housing and rod-coupler, acoupler-housing formed of an impact-resistant synthetic resinscrew-threadedly mounted to the threaded end of the glass barrel andhaving a piston-clearing passageway therethrough to permit the piston tobe fully withdrawn, a screw-threaded rod-coupler movably mounted to thecoupler-housing and arranged to be optionally moved into a couplingposition in which its thread interengages the thread of the piston-rodand into an uncoupling position in which its thread is out of engagementwith the thread of the piston-rod, said rod-coupler being arranged toprovide a radial clearance for the piston when the rod-coupler is in itsuncoupling position for permitting the piston to be fully withdrawn inan axial direction, and a handle carried by the outer extending end ofthe piston-rod.

12. A syringe, column or the like according to claim 11, in which thepiston-rod and piston are screw-threadedly telescoped to each other.

13. A syringe, column or the like according to claim 12, in which thescrew-threadedly telescoped portions of the piston-rod and piston arebonded to each other by a film of bonding resin intervening thejuxtaposed thread surfaces thereof.

14. A device according to claim 11, in which the coupler-housingincludes a channel transversely of the axis of the barrel and in whichthe rod-coupler is slidably disposed within and guided by said channel.

References Cited UNITED STATES PATENTS 949,163 2/ 1910 Stapley 222-3901,624,138 4/ 1927 Jorgensen et al 222--390 2,745,575 5/1956 Spencer222-390 X 3,146,142 8/1964 Maly 285-423 X 3,153,496 10/ 1964 Johnson222-386 3,212,685 10/ 1965 Swan et al. 222-386 N. L. STACK, AssistantExaminer,

11. A SYRINGE, COLUMN OR THE LIKE, INCLUDING A RIGID TRANSPARENT GLASSBARREL HAVING A GLAZED CYLINDRICAL BORE AND A DISCHRAGE HOLE OFSUBSTANTIALLY SMALLER DIAMETER EXTENDING FROM THE INNER END OF SAID BORETO THE EXTERIOR OF THE BARREL AND SAID BARREL HAVING ITS OTHER ENDSCREWTHREADED, A PISTON OPERATIVELY DISPOSED WITHIN SAID BORE FORMED OFA GENERALLY CHEMICALLY INERT AND GENERALLY FORM-RETAINING THOUGHSLIGHTLY RESILIENTLY DEFORMABLE SYNTHETIC RESIN CAPABLE OF FORMING ANUNLUBRICATED NONSEIZING SLIABLE FLUID-SEALING DRY CONTACT WITH THEGLAZED SURFACE OF SAID BORE, SAID PISTON HAVING AN INTEGRAL PISTON-RINGIN PROXIMITY OF EACH OF ITS TWO ENDS, SAID PISTON-RINGS BEING OF SMALLAXIAL EXTENT AND OF A DIAMETER WHICH IS LARGER THAN THE DIAMETER OF ITSBODY PORTION INTERMEDIATE THE PISTON-RINGS THEREOF AND WHICH ISSUFFICIENTLY LARGER THAN THE BORE OF THE BARREL IN THE UNCOMPRESSEDCONDITION THEREOF SO AS TO BE RESILIENTLY COMPRESSED WHEN THE PISTON ISOPERATIVELY DISPOSED IN THE BORE OF THE BARREL, A PISTON-ROD HAVING ITSINNER END AFFIXED TO THE PISTON AND HAVING A PORTION THEREOF EXTERNALLY